7261
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7452
- Proper Divisor Sum (Aliquot Sum)
- 191
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7072
- Möbius Function
- 1
- Radical
- 7261
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 57
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite CON = CIT-1 H2[B2Si54O112] starting with a T2 atom.at n=12A019095
- Numbers k such that the continued fraction for sqrt(k) has period 87.at n=2A020426
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 40 ones.at n=36A031808
- Base 5 digits are, in order, the first n terms of the periodic sequence with initial period 2,1,3,0.at n=5A037738
- a(n) = (9*n^2 + 3*n + 2)/2.at n=40A038764
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 23.at n=13A051988
- a(n) = min(x : x^2 + n^2 = 0 mod (x+n-1)).at n=60A066333
- Number of permutations p of [n] such that 1*p(1) + 2*p(2) + 3*p(3) + ... + n*p(n) is prime.at n=8A073114
- Pseudo-random numbers: gcc 2.6.3 version for 32-bit integers.at n=1A084276
- Numbers k such that each of k through k+4 are divisible by exactly two primes.at n=46A088986
- Number of partitions of 2n in which odd parts and multiples of 3 and 5 occur with even multiplicities. There is no restriction on the other even parts.at n=23A102346
- Expansion of -LambertW(-x^2*exp(x))/x^2.at n=6A125500
- Number of partial mappings (or mapping patterns) from n points to themselves; number of partial endofunctions.at n=9A126285
- Numbers k such that k and k^2 use only the digits 1, 2, 5, 6 and 7.at n=31A137004
- a(n) = 242*n + 1.at n=29A157958
- a(n) = 484*n + 1.at n=14A158326
- a(n) = 60*n^2 + 1.at n=11A158673
- a(n) = 3F0(-n,-n+1,-n+2;;-1/2) = n!*(n-1)!*2^(1-n)* 1F2(-n+2;2,3;-2), where nFm(;;) are generalized hypergeometric series.at n=4A174324
- Row sums of triangle A179901.at n=18A179902
- a(n) = 8*n^2 + 2*n + 1.at n=30A188135